Pyrophoric alloy.



', Be it known that I, PAUL sTATEsrAT-ENT cr mes; "1

rant-"Fauna, or nir'rnnrnnn, GERMANY, ASSIGNOR TO nnnc'rnocnnmlscim wanna.

G. M. 'B. .31., or BERLIN, GERMANY.

rrnorironrc ALLOY.

No Drawing. To all whom it may concern:

of the United States, residing: at Bismarck street, Bitterfeld, Germany, have invented certain newand useful Improvements I in Pyrophoric Alloys; and I do hereby deexact description of the invention, such clare the following to be a full,'clear, and as will enable others skilled in the art to which pyrophoric rare-earth -metal alloys have.

it 'appertain'sto make and .use the same;

' Recent'inv'estigations in the domain of 'shown that for the production of commer- .,--c;1ally utilizable products it is by no means necessary to have a percentage of iron.

Althou'gh Auer, in, his Austrian Patent No.

' 19251, expressly insists that with the complete substitution of iron, the pyrophoric gower is diminished in a way that cannot be i'sputed, this is by no means the-case. Very pyrophoric alloys can be obtained wlthout anaddition of iron, if zinc, cadmium, tin or lead is alloyed with cerium.

' Experiments to alloy zinc with cerium have heretofore" been made (see Abeggs Handbuch pier Anorgawisohen Uh'emz'e, 1906, vol.

111,part 1, page 195 but no sparking qualities whatever were observed in these alloys, and the described properties of the alloys in other respects were unfavorable to their commercial utilization The. pyrophorlc alloys hitherto known,

: which contain the rare earth metals are composed generally of single metals like:

'inanganesej, 1ron, nickel and cobalt and it 'would be entirely incorrect to suppose that -all',alloys of the rare earth metals possess "pyrophoric-properties. One must bear in mind that pyrophoricproperties are by no -Igneans possessed, as a rule, by the cerium alloys, and must be regarded in fact in every respect as exceptional. The cerium copper alloy for instancehas no pyrophoric properties whatever. Inthe periodic system copper is followed by zinc, and jud ing from the "bell alvior of co per one woul be led to suppose, thatthe zinc-alloy would also lack pyrophoric properties It is therefore sur- .Theelements directly fo risin that the zinc alloy should exhibit the I avora', 1e pyrophoric. profierties that ited oes.

periodicgsystemsare out of'the question for t e ii pdu t q o py ph i y 'oaa o jnt l Speciflc ation of Letters Patent. Application filed March 27, 1912. Serial No. 686,667.

owing zincin' t v I of their outer properties. The riext elements FAEHR, a citizen" following are silver and cadmium. The silver-cerium alloy is not pyrophoric, and

cadmium-cerium al oy used in this inven- In this connection it must be particularly taken into account that the cerium-cadmium alloy is altogether new. Hans Beck, who is the only one, who has investigated this subject, was unable to produce the cerium-cadmium alloys (Beck, Beitrdge 2m- Kenntm's tier Metalle der '(lcr-G'ruppe, Niirnberg 1907, seite 27, absatz 2..) The properties of the cerium cadmium alloys, which are described in this invention for the first time are likewise new and surprising.

the possibility of the existence of a ceriumcadmium alloy must be regardedas a surprising fact.- p

I have now ascertained that alloys of the rare earth metals with zinc, cadmium, tin and lead, may be produced, which possess the appropriate hardness and brittleness, and which exhibit the property of sparking to an extraordinary degree when rubbed or alloys are of a higher brilliancytha'n those of pyrophoric alloys heretofore known. Furthermore, the sparks, especially of the cadmium-zinc-and tin rare-earth metal alloys.- arehotter than those of the ceriumiron alloys heretofore known, and furtherditionwould Patented July '7, 1914.

tion are therefore 'all the more surprising.-

scratched. The sparks of some of these.

more; these new alloys are much more resistmixture with each other, and cerium can be.

in a careful manner to the melted cerium.-

the favorable pyro horic properties of the According to the publication of Beck even known. The metals cadmium, lead, zinc and furnace, it islikewise advisable not to unwhen the electric cirv a large portion'of the me'talsof adbe volatilized, if this should.

' be permitted, or would be lost by passing off into the slag. to be alloyed are mixe we then obtain thedesired alloys and without particular loss.

The proportions in which the zinc, cadmium, tin and lead are added to the molten rare earth metals depend of'course, .ent-irely upon the desired degree of pyrophoricity, the hardness and the other important tech nical qualities desired. The addition of the metals to the cerium has, among other things, the effect of increaslng the hardness of the cerium aside from the diminution of the pyrophoric effect. The quantity of the addition is controlled by the circumstance that with larger additions the hardness increases. Too great hardness is to be avoided, as it increases the difficulty of working the metal, and the'difliculty of, producing the sparks. Higher percentages of cadmium are permissible than of the other metals in making up the rare earth metal alloys in accordance with my invention.

By way of illustration, the composition of a few alloys that spark very well and that are economical inuse are given below, although these form, so to speak, merely samples .of a multitude of. possible combinations: 1. 40% cadmium wit-h 60% cerium; 2. 30% zinc 'with 70% cerium; 3. 30% tin with 70% cerium; 4. 30% lead with 70% cerium. When two or more of the alloying metals are added to the rare earth metal to form the desired alloy, the added metals may be in any appropriate proportions among themselves provided the aggregate of the additions represents the necessary proportion with respect to the rare earth metal. For example, if cerium be employed with the additional 30% consisting be .made. For certain purposes e. 9., for

miners lamps, too energetic an emission of sparks is not desirable; on the contrary, a compact flame is preferred. This property, is inherent in alloys of given proportions only. In order to vary their hardness and their heating effect, it is desirable, there fore, to make use of the addition of third metals, as suggested.

The-new alloys not only keep for an indefinite time when exposed to air but also in the (presence of moisture neither are they afl'ecte by great changes of temperature nor by belng placed in water. None of the 05 pyrophoric 'alloys hitherto known can fulfil If however, the metals d and carefully heated,

these conditions. The above mentioned properties are especially important for 'the ignition of miners lamps. have to be used by the miners for a 'long time in moist warm places. Consequently the safeness ofthe ignition becomes ques- 'tionable, as soon as the alloys used for the purpose of i nit'ion are acted on by moisture. Should this e the case the danger arises of not being able to ignite the lamps at all, or even if the ignition is faulty and uncertain the safety 'of .the miner can be imperiled.

The high temperature of combustion of the individual metal particles struck from the alloy must be especially emphasized as this is of the greatest importance in respect to the ignition of safety lamps. For tiny metal particles can pass through the meshes of the gauze into the open air in spite of all precautions and can cause the greatest disasters. in any shaft not free from fire damp, if the particles have a low combustion temperature.

These lamps Experiments carried out by the mining department have shown, that the unburned metal particles thrown off during the ignition can only be made to burn'with the greatest difliculty on account of their high that can not be asserted in regard to the known alloys.

The new alloys are particularly applicable to the ignition of gaseous or liquid fuels, and also to the ignition of explosive mixtures. Their property ofburning in a powdered condition with a high emission of heat and an intense radiation of light, makes them appropriate to the production of igniting and illuminating devices of the most varied kinds.

The so-called rare earth metals are difficult to separate and consequently it is almost always necessary in practice to use a mixture of cerium with lanthanum and didymium, that is to say, a mixture of the metals of the cerium group of the rare earth metals.

Having thus described my invention, what I claim is:

1. A metal alloycontaining a metal of the rare earth grou metals, zinc, ca mium, tin, or lead in such proportions as to make the alloy pyrophoric.

2. A metal alloy containing a metal of the rare earth grou and one or more of the metals, Z1110, ca mlum, tin, or lead in such proportions as to make the alloy pyrophoric,

and one or more of the with the addition of another metal for the alloy pyrophoric, with the addition of an-l .purpose of modifying the character of the other metal for the purpose of m0d1 sparks. the character of the sparks.

3. A metal alloy containing cerium and In testimony whereof I afiix my signa- 5 one or 1mo'e of t1: metals, zmc,.cadmiu1l1:1, ture, in presence of two witnesses.

tin, orea in $110 proportions as to ma 0 the alloy pyrophoric. PAUL FAEHR' 4; A metal alloy containing cerium and Witnesses: one or more of the metals, zinc, cadmium, JULIUs Rmnmnn, 1o tin, or lead in snch proportions as to make the KARL Bnmmmt. 

